/*
 * $AIST_Release: 0.9.0 $
 * Copyright 2011 Information Technology Research Institute, National
 * Institute of Advanced Industrial Science and Technology
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *    http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package aggr

import Aggregators._
import com.google.protobuf.ByteString
import scala.collection.mutable.MultiMap
import SerializedTypes.SerializedType
import Util._

/**
 * "collection" aggregator.
 */
class Collection extends Aggregator {
  // Do nothig
  override def aggregate(data: TraversableOnce[(Any, Any)])(writer: (Any, Any) => Unit): Unit = {
    data.foreach { case (k, v) =>
      writer(k, v)
    }
  }
}

class CollectionFactory extends AggregatorFactory {
  override def createNew(keyType: SerializedType,
                valType: SerializedType,
                args: List[Long]): Aggregator = new Collection

  override def check(keyType: SerializedType,
            valType: SerializedType,
            args: List[SerializedType], 
            options: Map[String, SerializedType]): Option[List[String]]= {

    val aggrName = "collection"

    checkNumOfArgs(aggrName, args.length, 0) ++ 
    checkOptionName(aggrName, options, Nil) match {
      case Nil => None
      case x   => Some(x)
    }
  }
}
